Engine mounting structure for all terrain vehicle

ABSTRACT

Disclosed is an all terrain vehicle with an improved engine and power train. The engine is located under the seat and the hingably seat provides for ready access to the engine for maintenance and repair. The engine is placed in the vehicle such that the crankshaft is parallel to the line of travel; that is to say that the crankshaft is in line with the longitudinal axis of the vehicle. The engine has a split output shaft; that is to say, two output shafts. One shaft extends forwardly of the engine to a front transmission on the front axle and the second extends rearwardly to a rear transmission on the rear axle. The output shafts run directly to the transmissions in a straight line. The front and rear output shafts are connected by gears which enables different ratios of revolution between the front and rear axle if necessary. The all terrain vehicle is also equipped with a unique parking gear which essentially locks the two output shafts to the transmission housing. There are a number of intermediate shafts such that power is transmitted from the crankshaft through two transmissions prior to reaching the output shafts. In addition, the gas tank is remote from the engine such that the cylinder head can be easily removed from the engine for servicing, repair and maintenance.

DISCLOSURE

[0001] This invention relates to an improved all terrain vehicle and more particularly to the placement and orientation of the engine and type of engine and power train.

BACKGROUND

[0002] All terrain vehicles have become quite popular in Canada and the United States in resent years. The original vehicles were built with three wheels and had a chain drive. Motors were generally oriented in the vehicle, having the crankshaft and drive shafts oriented transversally to the direction of travel. Such vehicles were found to be unsteady and did not have sufficient stability and power to work as utility vehicles.

[0003] In more recent years, all terrain vehicles have been developed with four wheels for greater stability and in fact four wheel drive. Generally, the orientation of the motor was such that the crankshaft and drive shafts extended transversally to the line of travel and chain drives or other gear mechanisms were used to drive front and rear axles.

[0004] In very recent times, some manufactures have oriented the engine such that the crankshaft is parallel to the line of travel and the longitudinal axis of the vehicle. In fact, some vehicles have a single output or drive shaft which extends through the motor and drives transmissions on the front and rear axles. Being a single shaft of course the gear ratio is identical between the rear axle and the front axle.

[0005] Other problems with recent all terrain vehicles is the failure to provide access to the engine for maintenance and repair. It is difficult to access things such as the oil filter, engine oil filler cap or remove the cylinder head. Therefore, there is a need to have a vehicle with ready access to the engine.

[0006] Another problem with recently manufactured all terrain vehicles is that the engine is too high and takes up to much space. Therefore a new more compact engine is desirable. Another problem with present day engines is failure to have a parking gear. The parking gear is desirable when one wishes to keep the engine on or park on a steep slope. It is also desirable to have engine placement in such a way so that the vehicle can be easily mounted by the operator without stepping over a high straddle seat. Thus there is a need to position the engine in such that that one may step through to mount the saddle or seat.

SUMMARY OF THE INVENTION

[0007] The present invention provides a motor which is mounted in the vehicle under the seat. The vehicle has a step through passageway in front of the seat. The motor provides drive to the rear axle and front axle by means of two output shafts. The output shafts are connected to one another in a type of split shaft arrangement. Gears transfer power from the crankshaft to the transmission. There after power is transferred to one output shift and thereafter to the second output shaft. Each output shaft, i.e. the rear and the front, are directly in line with the differential gears on the rear and front axles respectively. Thus there is an ease of manufacture.

[0008] The transmission of the vehicle of the present invention consists basically of intermediate shafts and two transmissions. A parking gear is also provided to lock the two output shafts to the transmission housing.

[0009] The engine is located under the seat, while the gas tank is located just below the steering counsel. The seat is hinged and provides easy access to the engine. Since there is no fuel tank on top of the cylinder head it is easy to remove the cylinder head for maintenance or repair.

[0010] In the present invention the transmission is integrated into the crankcase of the motor. Positioning the crankshaft, balancer shaft and cam shaft roughly in the same area (although not on the same plane), the lowest overall height of the engine is obtained. The engine of the present invention has a two valve design. It is a four cycle engine with one cylinder. Two spark plugs are used, similar to old aircraft engines.

[0011] An oil filler cap for the engine is located directly on top of the cylinder. Thus engine oil for the crankcase can be added with easy access. The oil sieve which is located on the bottom of the crankcase has an access cover and the oil sieve can be removed easily and cleaned.

[0012] The crankshaft of the present invention is connected to a centrifugal clutch. This is located forward of the crankcase between the clutch housing and the crankcase housing. Forward of the clutch housing is a clutch cover. A disengaging piston is found between the clutch housing and clutch cover. The all terrain vehicle uses a two clutch system which is well known in the art.

[0013] The present invention also has a parking gear. To the best of the inventors' knowledge a parking gear has never been used before in an all terrain vehicle.

[0014] The transmission used in the all terrain vehicle of the present invention is located within the crankcase housing.

[0015] The water pump used for the engine coolant in the present invention is novelly positioned at the end of the crankshaft at the rear end of the crankcase housing. No other all terrain vehicle places the water pump directly on the crankshaft itself.

[0016] The radiator for the water cooled system is at the rear of the engine close to the water pump. The radiator also has a fan which is located at the rear of the vehicle's engine.

[0017] The fuel tank has a low center of gravity and is positioned ahead of the engine. With regard to the air intake for the engine, it enters near the front of vehicle at the highest point to avoid water or mud entering the air intake. From there the air goes to an air box which houses an air filter and a silencer. Thereafter, the air is directed to the carburetor. The carburetor of the present all terrain vehicle is a standard carburetor.

[0018] The clutch housing and cover of the present invention is equipped with water coolant passages in the bottom water is routed through the bottom of the engine to cool the oil in the housing above. This is unique to all motor vehicle engines.

[0019] Therefore this invention seeks to provide an all terrain vehicle including a four cycle engine and a power train; said engine including a crankshaft; said engine being mounted in said vehicle such that said crankshaft is parallel to a longitudinal axis of said vehicle and parallel to a line of travel when said vehicle is in motion; said engine further including a rear output shaft and a front output shaft, said shafts being parallel to said crankshaft; wherein said rear output shaft in operation is adapted to supply power to a rear axle and said front output shaft is adapted to supply power to a front axle.

BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The invention will be described more fully in connection with the following drawings wherein:

[0021]FIG. 1 is a perspective view of the all terrain vehicle of the present invention;

[0022]FIG. 2 is a side view of the vehicle of the present invention;

[0023]FIG. 3 is another perspective view of the present invention showing some of the exterior components;

[0024]FIG. 4 is an underside view of the present invention shown in a schematic fashion;

[0025]FIG. 5 is a side view of the present invention showing some of the internal working components; the actual outline of the body and seat of the invention is shown in dotted lines;

[0026]FIG. 6 is a top view of the present invention with the body components thereon;

[0027]FIG. 7 is a side view of the present invention showing the seat in an open position for servicing of the motor;

[0028]FIG. 8 is a view of the basic frame of the present invention without body, motor, suspension or other components;

[0029]FIG. 9 is a perspective view of the motor mounted on the frame shown in FIG. 8;

[0030]FIG. 10 is a transverse cross section of the engine of the present invention;

[0031]FIG. 11 is an exploded view of the components of the crankcase of the engine of the present invention;

[0032]FIG. 12 is an exploded view of the various components of the cylinder and piston of the present invention;

[0033]FIG. 13 is an exploded view of the components of the clutch housing and clutch cover;

[0034]FIG. 14 is an exploded view of the components of the primary clutch and shift clutch;

[0035]FIG. 15 is an exploded view of the components of the gear shift assembly;

[0036]FIG. 16 is a cross section of the components of the parking gear;

[0037]FIG. 17 is a exploded view of the components of the transmission;

[0038]FIG. 18 is an exploded view of the components of the ignition and water pump;

[0039]FIG. 19 is an exploded view of the components of the electric and hand starters;

[0040]FIG. 20 is an exploded view of the components of the exhaust system;

[0041]FIG. 21 is an exploded view of the components of the cooling system; and

[0042]FIG. 22 is an exploded view of the components of the air intake system.

DETAILED DESCRIPTION OF THE INVENTION

[0043] In FIGS. 1 through 10 it is to be understood that the components maintain the same numerals throughout. However, in the remainder of the drawings, each drawing is described separately and the components listed therein. Thus, it is to be understood by the reader that similar numerals may appear throughout such drawings but such numerals relate only to the drawing to which they refer and that each drawing will be described separately.

[0044] In drawings 1, 2 and 3 are various views of the all terrain vehicle of the present invention 1. The vehicle has a pair of front wheels 2 and a pair of rear wheels 3. There is a front bumper 4, a front carriage rack 5, a rear carriage rack 6. There is a seat 7 which is positioned over the engine and is hingably mounted. As seen in FIG. 7, there is a hinge bracket 8 which hinges about pivot hinge 9.

[0045] The all terrain vehicle is equipped with a pair of handle bars 10.

[0046] Turning to FIGS. 4 and 5 one notes that there is an engine 11. As shown in FIG. 5, the gas tank 30 is mounted below the handle bars. Gas cap 12 closes the tank. As seen from the FIG. 6, foot rests 13 are found on either side of the seat 7. Also visible in FIG. 6 is that seat 7 has a seat latch 14 which can be lifted upwardly for access to the motor 11. As seen in FIG. 6 there is an instrument dash 15 located below the handle bars 10. The rear of the body of the vehicle forms rear wheel wells 16 and the front of the body forms front wheel wells 17. In FIG. 3 one of the front shocks 18 is visible.

[0047] The all terrain vehicle of the present invention is equipped with a front compartment 19. In FIG. 7 one views that the cover of the front compartment is open. The compartment can be used for storage of various items.

[0048] In FIG. 4 one sees an exhaust pipe 20 leading from the motor to a muffler 21. Also viewed in FIG. 4 is a rear axle 22 and a front axle 23 on which are located respectively rear differential 25 and front differential 24. A front output drive shaft 26 is pivotally connected to motor 11 and front differential 24. A rear output drive shaft 27 similarly is connected to motor 11 and rear differential 25. It is to be noted that because of the orientation of the motor with the crankshaft being parallel to the longitudinal axis of the vehicle, the two output shafts 26, 27 are also substantially parallel to the crankshaft and the line of travel. As visible in FIG. 5 the vehicle is also equipped with rear shock absorbers 28. The frame is generally shown as 29 in drawings 1 through 10.

[0049] In FIG. 8 the frame 29 is shown without any other components. Step 13 has been marked as it forms part of the basic tubular type frame. It is to be understood in FIG. 8 that the frame is lower in the mid-section to allow for the step through feature which is an important part of the improved all terrain vehicle.

[0050]FIG. 9 is a perspective view of the mid and rear portions of the tubular frame or chassis of the vehicle with the motor 11 mounted therein. To the rear of the frame is mounted fan 31, and a radiator 32. A radiator cap 33 is visible. Radiator inlet hose 34A leads from the water manifold of the engine 11 to the radiator 32. Radiator outlet hose 34B subsequently leaves the bottom portion of the radiator 32 and travels to the engine 11 where it is fixedly connected.

[0051] Unlike other all terrain vehicles where the engine compartment is difficult to get access to, the hinged seat 7 of the present invention provides ready access. Furthermore, the crankcase oil filler opening is found at the top of the cylinder head 37 and is covered by a oil filler cap 35. Because the gas tank 30 is distant from the engine 11 rather than being located on top of the engine as is in so many cases, particulary in motorcycles, the cylinder head can be readily accessed for repair. Also in FIG. 9 the oil filter 36 is visible and similarly easily accessible. FIG. 10 is a transverse section through the engine itself. As was previously mentioned the engine is positioned on the all terrain vehicle such that the crankshaft 44 is parallel with the longitudinal access of the vehicle and runs from front to back. The rear output shaft 27 is visible in this particular section however the front output shaft 26 is not visible. Below the cylinder head 37, one sees a valve spring 38 around valve 39. The engine of the present invention is equipped with two inlet valves 39. The single cylinder and piston motor of the present invention also uses two spark plugs for the single cylinder, similar to some aircraft engines.

[0052] A rocker arm 40 is pivotally connected to a push rod 41 which in turn is moved upwardly and downwardly by a cam shaft 42. Push rod 41 causes the opposite end of the rocker arm to move upwardly and downwardly in accordance with movement of the cam shaft 42 to open and close the valves 39 accordingly.

[0053] The cam shaft 42 is positioned above the balance shaft 43 which is located just to one side of the main crankshaft 44. From crankshaft 44 is a pivotal connection to connecting rod 45 which connects to piston 46. Piston 46 moves upwardly and downwardly within cylinder 47. Transmission shift forks 48 are visible on rear output shaft 27 and main shaft 52. Above main shaft 52 is countershaft 51.

[0054] A pawl assembly 49 functions as a parking brake. The parking brake secures front output drive shaft 26 and rear output drive shaft 27 to the transmission housing and locks the vehicle in a park position. Front output shaft 26 is not visible in FIG. 10.

[0055] Motor countershaft 51 is located above the main shaft and parallel thereto. Mounting points 53 are also shown. Also shown in FIG. 10 is the shift shaft 54, tension spring 55 and shift drum assembly 56. The pawl assembly 49, tension spring 55, shift shaft 54 and shift drum assembly 56 are components of the gear shifter.

[0056]FIG. 11 is a schematic exploded view of the basic components of the crankcase 1 of the present invention. The crankcase consists of two halves marked 1. The single cylinder of the engine of the present invention is not shown, however it obviously fits between the two halves of the crankcase 1 which are fastened together about crankcase gasket 40. There are a number of ball bearings 4, 6, 7 and 9. A roller bearing 8 is also shown. Intermediate gear shaft 10 is shown along with its placement in the crankcase housing. Socket screws 11 and flange hex screws 12 are used to secure the housing together. The oil pump roter assembly is shown basically as 13 and 14 in a rotor is marked as 14. The oil pump shaft is marked as 15. There is a needle pin 16; an oil pump cover 17; a thrust washer 18; needle pin 19; and socket screw 20. The oil pump gear which has 40 teeth is marked as number 21.

[0057] At the bottom of the crankcase is an oil sieve 25, an o-ring 26, an oil collector 27, a rubber ring 28 and an oil sieve cover 29. These are secured by hex screws 30 to the bottom of the crankcase housing.

[0058] In this particular engine which forms part of the invention, one notes to the left of the crankshaft also within the crankcase housing, a location which houses the transmission. In other words the transmission functions within the crankcase housing 1. The various shafts which rotate within the crankcase such as the cam shaft 42, balance shaft, main shaft and other shafts not shown in FIG. 11, however shown in FIG. 10 as 42, 43, 44, 27, 51, 52, 54 are secured at their ends through ball bearings 36, 37, 38, 39. The valve seat sleeve 41 is shown near the bottom of the drawing as well as a valve piston 42 compression spring 43, o-ring 44 and plug screw 45. A pair of cylindrical pins 46 are adapted to pass through the crankcase housing.

[0059] Solenoid valve 49 is also shown in FIG. 11 and is adapted to fit an the crankcase housing 1 with solenoid valve gasket 48. Items marked 50 to 54 simply indicate the type of lubrication used for the various parts of the crankcase housing.

[0060]FIG. 12 is a schematic view of the components of the piston and cylinder. The cylinder shown as 4 is fixedly attached with cylinder gasket 3 to crankcase housing 1. Piston 5 along with piston ring set 6 is attached by piston pin 7 to a connecting rod (not marked) which forms part of the crankshaft assembly 9. A woodruff key 10 is used to secure a 42 tooth mating gear 11 to the end of the crankshaft with hex nut 12. Adjacent to crankshaft assembly 9 is balance shaft 13 which is adapted to pass through a balancing shaft gear 14, control gear 15, lock washer 16 and hex nut 17.

[0061] Adjacent to balance shaft 13 and generally positioned above the same when installed in the engine is the cam shaft 18 which passes through a cam shaft gear 19 secured by a needle pin 20. The deco shaft assembly 21, 22 has a groove pin 22 and centrifugal weight 23, tension spring 24 followed by a washer 25, block washer 26 and hex screw 27.

[0062] A water cooling hose 29 by way of clamps 28 is connected to the cylinder wall and the crankcase housing 1. At the top of FIG. 12, a bayonet filler cap 31 is found on valve cover 34. Valve cover 34 is attached to cylinder head 51 with valve cover gasket 35, hex screw 32 and rubber bushing 33. Push rod 36 is adapted to move upwardly and downwardly rocker arm 37 which is adapted to move valves 53 and 54. Valve cotter 38, valve spring retainer 39, valve spring 40 and valve seal 41 and washer 42 are inserted on the valves. A temperature sensor 43 is adapted to be mounted to the cylinder head 51. Cylinder head gasket 52 is adapted to be placed between the cylinder head 51 and cylinder 4. Rocker arm 37 pivots about rocker arm shaft 58 which is secured by holding strip 59 and a socket screw 60 onto the top of cylinder head 51. The engine of the present invention uses two spark plugs for the single cylinder. Also located on the top of the cylinder head 51 is thermostat 48 which fits within thermostat housing 47 which is secured by hex screw 45 and seal washer 46. The engine is also equipped with a hydraulic valve tap at 55.

[0063] In FIG. 13 clutch housing gasket 9 is inserted between clutch housing 1 towards the front of the vehicle to the crankcase (previously shown in FIG. 11). Within the clutch housing 1 is located a first centrifugal clutch to be described later. A disengaging piston shown as 19, 20 is located between the clutch housing 1 and the clutch cover assembly shown as 21. Clutch cover 21 attaches to the clutch housing 1 by means of clutch cover gasket 14.

[0064] Of particular interest in the present invention are the water channels shown as 60 which are in both the clutch cover assembly 21 and the clutch housing 1. These water channels move coolant into the bottom of the clutch housing and clutch cover and cool the oil above.

[0065] In detail, ball bearings 2 and 3 fit within the clutch housing 1. Flat head screws 4 are shown. On the bottom of the housing is an o-ring 5 and a drain plug 6. Also located at the bottom of the clutch housing 1 is a washer 7 and screw 8. As previously mentioned, the clutch housing gasket 9 is used to seal the clutch housing to the crankcase. Hex screws 11, 12 and 13 secure the clutch housing 1 to the crankcase. On the top of clutch housing 1 is an oil filter 17, an oil dipstick 18, and oil filter nipple 16. Between clutch housing 1 and clutch cover 21 are located oil seal 22 and ball bearing 23. There is also a tube 24.

[0066] Forward of the clutch cover 21 is ball bearing 25, retaining ring 26 and oil seal 27. A solenoid valve 29 is secured into clutch cover 21 by means of a socket screw 30. A potentiometer 31 with the aid of washer 32 and socket screw 30 is secured to the front end of clutch housing 21.

[0067] A pressure valve 33 is also affixed to the outside of clutch cover 21. The oil duct cover 35, which has a gasket 34 is secured by hex screws 37 and washers 38. The cable clip 36 is also inserted on the top of oil duct cover 35. An oil cooler cover 40 is attached by a screw with gasket 39, also on the front end of clutch cover 21. Hex screws 42 and 43 secure clutch cover 21 to clutch housing 1. An oil pressure switch 47 protected by an oil seal 46 is inserted in the front of clutch cover 21. A speed sensor 48 is secured by hex screw 49. A water cooling hose 51 which leads to cooling channels 60 is secured by clamps 50. Hose clamps 52 and S3 support water cooling hose 51 in position. Hex screws 54 support the clamps.

[0068]FIG. 14 illustrates a two clutch system of the present invention which is found between the clutch housing 1 and clutch cover 21. There is a primary centrifugal clutch and a shift clutch. Primary centrifugal clutch, shown in the upper right portion in the drawing is connected to the crankshaft.

[0069] The shift clutch is driven by the centrifugal clutch. The shift clutch consist of a thrust washer 1 and needle bearing 2, a needle cage 3 and a clutch drum 4. The clutch drum 4 is equipped with a gear. Thereafter there is an o-ring 6, a thrust washer 6, an inner plate 7 and a plurality of lamella 8 and plates 9. A clutch hub 10 secures the lamella to the inner plate 7 and the clutch drum 4. This is followed by a spring 11, washer 12, hex nut 13, a retaining plate 14, ball bearing 15, and thrust hub 16. All are secured by a hex nut 18 and washer 17.

[0070] With regard to the primary clutch which is connected to the crankshaft, there is a thrust washer 19, a bushing 21, a gear (unnumbered), a clutch assembly 20 comprising a clutch bushing 21, a sprag clutch 22, a clutch hub 23, a serrated washer 24 and a hex nut 25.

[0071] In FIG. 15, the gear shift is shown in an exploded section. The components of the gear shift, although known in the auto industry, particularly the parking gear components have never been used before in an all terrain vehicle. Thus, this forms part of the present invention.

[0072] Beginning at the bottom of FIG. 15, there is a thrust washer 1 with a screw and gear shift lever 3, a sleeve 4, a washer 5, a shaft spring 6 and a collar sleeve 7. These are placed on the shift shaft with pawl assembly 8. A tension spring 9 secures them.

[0073] To secure the assembly together there is a socket screw 10, a washer 11, an index lever assembly 12, a bushing 13 and an index lever spring 14. On the opposite end there is a socket screw 38, washer 11, index lever assembly 12, bushing 13 and spring 14. There are plurality of shift forks 15, 16, 17, 18 and 19 for the changing of gears. Shift forks 18 and 19 fit on gear shift rod 20 whilst 15 and 17 fit on rod 22 and shift fork 16 fits on rod 21. Also a shift drum assembly 23 and shift 24. Screw 25 secures the assembly together.

[0074] At the opposite end of the housing is index gear 26 secured by socket screw 27. The shift shaft assembly is shown as 28. There is a shaft 29, a park locking lever 30 an actuated lever 31, a spring 32, a sleeve 33, thrust washer 34, tension spring 35, an indicator shaft 36 and o-ring 37. Socket screw 38 secures washer 11, index lever assembly 12, bushing 13 and index lever spring 14 into position.

[0075]FIG. 16 is a cross-section of a cut away close up view of the parking gear assembly. There is a tension spring 35, a shift shaft 29, a parking lock lever 30, an actuating lever 31 and a helical spring 32. Also shown is front output shaft 26, a rear output shaft 27, and a parking gear 61. Also shown is a shift drain assembly 62 and an indicator shaft 63.

[0076] Turning to FIG. 17 and as previously mentioned, the components of the transmission are found side by side within the crankcase housing. There is a countershaft 1, a main shaft assembly 2, an intermediate gear shaft 3 and a thrust washer 4. Intermediate gear shaft 3 passes through sliding gear 5, needle cage 6, washer 7 and socket screw 8 to secure these components. The rear output shaft 9, which is directed towards the rear axle and differential previously described, is attached to output gear 10 and secured by a Circlip 11. The front output shaft 12 has o-ring 13 thereon. Front output shaft 12 supplies power to the front axle and front differential, as previously mentioned. As can be seen the five gear forks are present in FIG. 17 as well as the gear drum assembly.

[0077]FIG. 18 is an exploded view of the ignition and water pump assembly. The ignition cover 2, by way of ignition cover gasket 1, is secured on the rear of the crankcase shown in FIG. 11, as previously mentioned by means of screws 3, 4 and 5. A potentiometer 6 by way of o-ring 7, washer 9 and screw 8 is secured at the rear of the ignition cover 2. An oil seal 10 is also inserted into the rear of ignition cover 2. Connected directly to the crankshaft is water pump shaft 11, oil seal 12, water impeller 13 and water pump housing 15 secured by screw 16.

[0078] It is novel to the present invention to have the water impeller 13 and water pump housing 15 directly connected to the crankcase. A rubber ring 14 seals the impeller to the housing 15. A hydraulic piston is adapted to fit within the ignition cover 2 by means of rings 17, hydraulic cover gasket 19, hydraulic cover 20 and hex screw 21. The magneto assembly 33 is adapted to fit within the ignition cover by means of a clamp 22, a seal 23, a bearing 24, distance sleeve 25, a needle pin 26 and a pawl 27.

[0079] The magneto assembly shown in greater detail in the enlarged part of the drawing comprises a female housing of 6 circuits 41, an adapter 42, a gasket 43 and gasket 44. Screws 28 and 29 secure the magneto assembly. Also hex nut 31, washer 32 and a rotor with a sprag clutch assembly 34. This is secured by a socket screw 35. There is a sprag clutch 36 and a sprag clutch housing 37. Cable clamp 38 also secures the magneto assembly.

[0080]FIG. 19 illustrates the manual starting assembly and the electric start assembly. The manual start assembly is located on the end of the crankshaft forward of the clutch cover, whereas the electric starting assembly is located close to the crankcase. Starting from the rear and progressing forward is a needle cage 1, a ring gear 2, and a ring 3. The crankshaft 44 (as shown in drawings 1 through 10) is shown in dotted lines.

[0081] There is a starting pulley 4, an o-ring 5, a hex screw 6, a screw 7, a flat washer 8, a locking spring 9, a stage sleeve 10 and a pawl lock 11. The pawl is marked as 12.

[0082] A key clamp 13 is inserted between the pawl and the rope sheave 14. A starter rope 15 is wrapped about the rope sheave 14. A rewind spring 16 (as is in other starters) is inserted within the starter rope housing 17. All is secured by a screw hex 18. The rope 15 once pulled through the housing 17 is attached to a handle starting grip 19 in a normal manner.

[0083] Turning to the starting motor, there is a hex screw which secures electric starter assembly 21. A cylindrical pin 22 secures double gear 23 to thrust washer 24 and spacer 25. The electric starter assembly is a typical component and not part of the invention.

[0084]FIG. 20 is a schematic, exploded view of the components of the exhaust and engine system. The exhaust exits through the front of the engine but is turned directly, rearwardly through tuned pipe 1 which is coupled by gasket 2 to the engine. A hex nut 4 by a stud 9 couples the tuned pipe to the engine. Screw 3 secures it to a bracket on the engine. Tuned pipe 1 fits directly into muffler 5. Rubbers 6 are secured to the rear of the frame. A heat shield 11 protects the heat of the muffler from the rest of the vehicle by means of hex screws 12. Springs 13 attach the tuned pipe 1 to the muffler 5. The motor in this drawing is shown as 14. As previously mentioned, motor 14 has a single cylinder however, it has two spark plugs 15 similar to aircraft engines but unique to all terrain vehicles.

[0085] Also shown in FIG. 20 is a support bushing 23. This is supported by flanged hex screw 27. Engine bracket 16 is adapted to attach to the end of the manifold of engine 14. By means of hex screw 27 the anti-vibration mount 20 with o-ring 22 support bushing 23 reduces the vibration caused by the exhaust system. Similarly engine bracket 26 secured by anti-vibration mounts 20, o-rings 22, support bushings 23, 24 and o-rings 22 support the other engine mount. Thus, three engine mounts are shown in FIG. 20. The carburetor 33 is supported on motor 14 at the top of the cylinder by means of clamp 34, carburetor adaptor 31 and clamp 32. Screws 30 are used to secure bracket 16. A choke cable lever 37 is attached to a choke cable 35 by means of plastic nut 36, lock washer 37 and is secured to the engine by tie raps 38 and 18.

[0086] Numeral 39 is the lever assembly. It has a lever button 40, a nylon bushing 41, an aluminum bushing 42 and a lever spring 43, which are secured by a hex screw 44. There is an upper tube 45 and a lower tube 46. Hex flanged screw 47 and clamp retainer 49, along with half ring 50, hex screw 51 and elastic flanged stop 52 secure the assembly together. At the bottom of the assembly is a right hand ball joint 53 and a left hand ball joint 54. Hex right hand jam nuts and hex left hand jam nuts 55 and 56 respectively are secured. A tie rod 57 is located between the ball joints 53 and 54. An interlock cable is provided and is secured by clevis pin 59 and cotter pin 60.

[0087] Turning to FIG. 21, this is a schematic view of the components of the cooling system. The principal components are found to the rear of the vehicle behind the motor. The motor is shown in dotted lines and marked as 64. The radiator is marked as 1, it has a temperature sensor 2 located near the bottom of the radiator. The radiator is attached to the frame of the vehicle by means of bushings and grommets, 4 and 3 respectively.

[0088] Attached to the rear of the radiator is an outlet deflector 5. A fan assembly 7 is attached to the outlet deflector 5 by means of fan support 8, hex screw 9 and nuts 6. Hex screws 10 attach the radiator 1 and outlet deflector 5 to the frame. Washers 11 and elastic flanged nuts 12 are located at the opposite end of the brackets on the radiator.

[0089] The radiator pressure cap is marked 13. The radiator inlet hose 14 runs from the top of the motor 64 to the upper opening of the radiator 1. Clamps 18 secure either end. An outlet radiator hose 15 runs from the bottom of the radiator 1 out to a lower portion of the motor 64 and is clamped in place. The lower hose has a protective shield 16 and the upper hose has a protective shield 26 in case of excess heat. Tie raps 17 and 28 secure the hoses in place. The radiator is also equipped with an overflow meter hose 23 which is secured to a nipple (not shown) on the radiator by means of a clamp 24. The meter hose runs to a coolant tank 19 which has a cap 20 and male connector 22 fits onto meter hose 23 by means of clamp 24 and fits through a grommet 21. The coolant consists of a mixture of antifreeze and water.

[0090] In FIG. 22, the air intake system is shown in schematic view. The air enters at the front of the vehicle at the highest place. This is to eliminate entry of mud or water splashed up from the wheels. The air intake pipes 14, 16 and 17 lead to an air intake silencer or air box 1. Rivets 2 secure the box 1. Internal reinforcement 3 is present. Air from the air box 1 leads through a hose 6 which is held by a clamp 10 to the carburetor 65. Clamps 10 also secure front air intake tube 14 to sleeve 16 to rear air intake tube 17. Air is moved to the engine valve cover and the engine by means of vent hose 22, clamps 18 and 19, PCV valve 21, gear clamp oetiker 27, vent hose 26, “Y” fitting 28, hose 29, hose 30 and fitting 33.

[0091] An air filter 32 is placed in the air box along with some foam 20. Air intake tubes 11 fit within the air filter. A cover 25 is secured by cover bracket 7 to the air intake silencer 1. The heat projector 5 is located on the side of the air box. Components also include a spring 13, train tube a and clip retainer 9.

[0092] In summary the present invention contains a number of inventive aspects, all of which will be set forth in the following claims. 

The embodiments of the invention in which an exclusive property or privilege is claimed and defined as follows:
 1. An all terrain vehicle including a four cycle engine and a power train; said engine including a crankshaft; said engine being mounted in said vehicle such that said crankshaft is parallel to a longitudinal axis of said vehicle and parallel to a line of travel when said vehicle is in motion; said engine further including a rear output shaft and a front output shaft, said shafts being parallel to said crankshaft; wherein said rear output shaft in operation is adapted to supply power to a rear axle and said front output shaft is adapted to supply power to a front axle.
 2. An all terrain vehicle as claimed in claim 1, wherein said output shafts are in communication with one another by means of gears fixedly attached to said shafts.
 3. An all terrain vehicle as claimed in claim 2 wherein one of said output shafts is in direct communication with a transmission by means of gears.
 4. An all terrain vehicle as claimed in claim 1 wherein said rear output shaft is connected directly to a rear differential gear on said rear axle and said front output shaft is connected directly to a front differential gear; said shafts being parallel to one another and being positioned along a line which is the shortest distance between said engine and each of said axles.
 5. An all terrain vehicle as claimed in claim 1 wherein said output shafts, in operation, rotate at the same speed.
 6. An all terrain vehicle as claimed in claim 1 wherein said output shafts in operation rotate at different speeds.
 7. An all terrain vehicle as claimed in claim 1 wherein said engine comprises a single cylinder and combustion chamber, said cylinder including a cylinder head and a valve cover, said valve cover including an engine oil filler cap whereby in operation said filler cap is easily accessible to fill said engine with engine oil.
 8. An all terrain vehicle as claimed in claim 7 further including gasoline tank, said gasoline tank being positioned on said vehicle remote from said engine.
 9. An all terrain vehicle as claimed in claim 1 including a water pump; said water pump being connected to said crankshaft and rotating at the same speed as said crank when in operation; said water pump being located to the rear of said engine.
 10. An all terrain vehicle as claimed in claim 1 wherein said crankshaft is housed within a crankcase; said crankcase further housing a transmission; said transmission further comprising a parking gear whereby, in operation, when said parking gear is activated, said front and rear output shafts are locked against a transmission housing.
 11. An all terrain vehicle as claimed in claim 7 wherein said cylinder includes two input valves and two spark plugs.
 12. An all terrain vehicle as claimed in claim 1 wherein said power train includes a centrifugal clutch connected to said crankshaft and a shift clutch; said clutch as being housed between the clutch housing and the clutch cover.
 13. An all terrain vehicle as claimed in claim 1, said vehicle including a hinged operator, seat, said seat being located substantially above said engine, said seat in an open position permitting free access to most engine components. 